Resistor structure



Feb. 28, 1956 R. E. DU BOIS RESISTOR STRUCTURE 2 Sheets-Sheet Filed Nov.12, 1955 .HHIIIILF INVENTOR ATTORNEY Feb. 28, 1956 DU 015 2,736,786

RESISTOR STRUCTURE Filed Nov. 12, 1953 2 Sheets-Sheet 2 5 5 7 5 6 I 1 Qa {3 i l r F 5 l I I i i fly] a i l a F i i L90- l i s? i w N a W30 5 WO \izgfi I N VE NT( )R ATTORNEY United States Patent RESISTOR STRUCTURERobert E. Du-Bois, Hammond, Ind. Application November 12, 1953, SerialNo. 391,569

4 Claims. (Cl. 201-69) This invention relates generally to improvementsin resistor structures and more particularly to resistor structures madeup of a plurality of individual resistor grid units.

The primary object of this invention is to provide an improved andsimplified resistor structure consisting of a plurality of readilyremovable and replaceable individual grid units.

A specific object of this invention is to provide a group of individualremovable resistor grid units housed in a common frame with a pluralityof terminals.

Another object of this invention is to provide a new and improvedterminal structure with its attending securing structure in a resistancestructure.

A further object of this invention is to provide an improved mountingstructure for a plurality of grids in the frame of a resistor structure.

With the foregoing and other objects in view the invention resides inthe following specification and appended claims, certain embodiments anddetails of construction of which are illustrated in the accompanyingdrawings, in which:

Figure 1 is a partial view in front elevation of the resistor structureof the invention;

Figure 2 is a bottom plan view of the structure illustrated in Figure 1;

Figure 3 is a sectional end view taken along the lines 3-3 of Figure 1;

Figure 4 is a partial view in section of the! structure in frontelevation; and

Figure 5 is an exploded view of the various resistor details andadjuncts thereof included in the resistor structure of this invention.

Referring more particularly to Figure 1, the resistance structure 1includes channel-shaped end frame members 2 (only the left end memberbeing shown), a top member 3 and end frame connecting rails 4. Theseframe members are welded together into a rigid unit. Welded to theunderside of top members 3 are a pair of angle members 5 and 6.Frictionally held between the angle members is an insulator strip 7. Thestrip 7 is provided with a plurality of evenly spaced holes 8 for apurpose to be later described.

Referring more particularly to Figures 2 and 3 it may be seen that thebase 9 comprises a plurality of insulator sections 10 and 11. Sections10 and 11 are provided with complementary slots 12 and 13 to accommodateand hold terminal elements 14. The insulator sections 10 and 11 aresecured in position by through bolts 15 which extend, as shown frombelow the insulator sections, to the upper side of top member 3. Thehead 16 of each bolt is spaced from member 3 by a washer 17. Thethreaded end of each bolt is provided with a nut 18 pressing, whentightened, against a washer 19. With the bolts 15- secured in thismanner the insulator sections 10 and 11 are held firmly against framerails 4.

Within the frame members are a plurality of grids 20.

2,736,783 Patented Feb. 28, 1956 Adjacent grids are alternately bridgedat one end electrically by conducting blocks 21, the blocks being weldedto the grids. Welded to the blocks 21 at desired points are the terminalelements 14; the ends of grids 20 which are not bridged by blocks 21 arebridged by conducting elements 22, said grids being welded to theelements 22. Each element 22 is provided with a pair of projecting guidepins 23. I

As illustrated, particularly in Figures 1 and 2, the grids 21 andinsulators 10 and 11 are formed in units 24, 25 and 26. Each of theunits includes several grid-s, terminals, bridging blocks, insulators,and connecting elements. It will now be obvious that in order to connectall of the resistance units together, it will only be necessary toelectrically connect adjacent terminals 27 and 28, and 29 and 30together by suitable means, not shown. This connection is desirablyreadily removable in order that an entire resistance unit may be removedfrom the structure should any of the grids become damaged.

To remove a unit from the structure 1 it is merely necessary to removethe retaining nuts 18 from bolts 15 holding the particular unit inplace. When this is accomplished, the bottom insulator sections 10 and11 will drop out and divide, permitting the connected grid assembly ofthe unit to drop out of the structure 1. A replacement unit may then besubstituted by merely replacing the sections 10 and 11 about theterminals 14 of the new unit and rebolting the said sections to theframe. Obviously the pins 23 of elements 22, during re-assembly, arepositioned in holes 8 of insulator strip 7 to guide and retain the topend of the grid assembly, as viewed in Figure 1. Under conditions of useof the resistor, the heat generated in each grid, due to the passage ofcurrent, will cause the same to expand longitudinally in pairs. The pins23 under non-use conditions of the resistor, will only extend partlyinto holes 8. Under heated or use conditions the pins will freely moveupwardly in the holes, thereby permitting the expansion of the gridswhile preventing the buckling of the same.

It should now also be readily appreciated that by providing a pluralityof terminals 14, any amount of desired resistance for a particularcircuit use may be had by merely selecting the proper terminals forconnection in the circuit.

Thus, it is seen that this invention provides a simple, compact andeconomical resistor structure which will lend itself to many uses withboth ease of assembly and disassembly, as well as practicability ofmanufacture.

I claim:

1. A resistor structure comprising a supporting frame, a plurality ofgrid units within said frame, insulator means secured to the frame forfreely carrying the tops of the grid units, insulator means for holdingand positioning the bottoms of the grid units, and means for removablysecuring said bottom grid unit insulator means to the frame to permitready removal of the grid units from the frame.

2. A resistor structure comprising a supporting frame, a plurality ofgrid units within said frame, insulator means secured to the frame forfreely carrying the tops of the grid units, divided insulator means forholding and positioning the bottoms of the grid units, and means forremovably securing said divided insulator means and thereby the gridunits to the frame.

3. A resistor structure comprising a supporting frame including a topmember, end members connected to the top member, means adjacent thebottoms of the end members for connecting said end members rigidlytogether, a plurality of grid units with said frame, each unit includingindividual grid elements connected alternately at their tops byconducting elements and at their bottoms by condue-tor bloc-ks with eachelement having guide pinsextending therefrom and each block having aterminal extending therefrom, an insulator strip provided With aplurality or' spacedholessecured to the under-side of the top-framemember, divided insulator members enclosing the-extendingterminals ofthe-grid units to positionand hold said units, and means cooperatingwith said divided insulator members to removably secure the grid unitsWithinthe frame.

4 A resistor structurecornpri-singa supporting frame, a plurality ofgrid units within said frame, each grid-unit havingat least oneextending terminal, insulator means securedto the frame forfreelycarrying and positioning- References Cited in'the file of this patentUNITEDSTATES PATENTS 684,791 Cal'ichofi v Oct. 22, 1901 1,755,350Fahrenwald' Apr; 22, 1930 2,156,832 Ayers May-2,1939

